This invention relates to a cross country ski binding and in particular to a cross country ski binding which enables a skier's boot to separate from the ski when the binding is subjected to forces which, if the boot did not release, may cause injury to the skier or damage to the boot.
There have been problems with conventional cross country ski bindings which use raised pins mounted to the ski for securing the ski boot to the ski. These problems have become more acute in recent years due to the fact that nordic skiers are using cross country skiis in a more strenuous manner than has been the case heretofore. For example, persons are using "telemark" ski techniques in skiing on downhill slopes and are using nordic skis in mountainous terrain on steep inclines.
There have been substantial developments in boot design to enable cross country skiers to ski under these conditions. Most commonly, the boots have been made of stronger materials and are made of sturdier construction. However, there remains problems with the ski bindings themselves because the raised pins tend to deteriorate female portions of the ski boot which receive the pins causing the ski boot to be held less securely to the ski. Very frequently, cracking and tearing of the boot sole where the female portions are located occurs after limited use of the boot. This requires either boot replacement or boot repair since this cracking or tearing quickly leads to complete failure of the sole. Furthermore, there have been safety problems with these conventional nordic ski bindings because they do not release the boot from the ski under, for example, twisting conditions. This has resulted in injury to skier's legs, knees and ankles.
In recent years releasable ski bindings have been developed for use with nordic skiis. Releasable bindings are well known in the downhill ski industry but are not very well known and have seldom been used with nordic skiis. One releasable safety binding developed for nordic skiis is described in U.S. Pat. No. 4,348,036 to Settembre. This patent describes a safety binding for cross country skiis that is capable of releasing a ski boot when the binding is over stressed by forces acting in any direction. This patent describes a ski binding which has a toe piece mounted to the boot with screws. The toe piece is releasably clamped between the arms of a scissor mechanism mounted to the ski. Biasing means act between the arms of the scissor to urge the scissor members into a closed position thus releasably holding the boot of the skier to the ski.